NTRK1 and hereditary sensory and autonomic neuropathy type 4: In a CIPA pedigree, we identified a known East Asian hotspot splicing variant, c.851-33T>A, and a novel intronic variant, c.850 + 5G>A, in NTRK1. Analysis of the intronic variant, c.850 + 5G>A, revealed the generation of two truncated proteins, as well as a decrease in mRNA and protein expression levels, ultimately leading to the development of CIPA.